High-speed angle-handpieces for dental purposes



Feb. l1, 1964 E. HOFFMEISTER ETAL HIGH-SPEED ANGLE-HANDPIECES FOR DENTAL PURPOSES Filed 001'.. 8, 1958 5 Sheets-Sheet 1 Feb. ll, 1964 E. HoFFMElsTER ETAL 3,120,705

HIGH-SPEED ANGLE-HANDPIECES FOR DENTAL PURPOSES Filed oct. a, 1958 5 sheets-sheet 2' @M/ww I JM, I

E. HoFFMl-:lsTER ETAI. 3,120,705

HIGH-SPEED ANGLE-HANDPIECES FOR DENTAL PURPOSES Feb. 11, 1964 5 Sheets-Sheet 3 Filed OGL 8, 1958 MN Q .mUAl M, w, o. .N mow QN www wm.

Feb. 11, 1964 3,120,705

HIGH-SPEED ANGLE-HANDPIECES FOR DENTAL PURPOSESA E. HOFFMEISTER ETAL 5 Sheets-Sheet 4 Filed 0012. 8. 1958 EAS/2J( MW JM @Map/@ mmJn Feb. 11 1964 E. HoFFMr-:lsTER ETAL 3,120,705

HIGH-SPEED ANGLE-HANDEIECES FOR DETAL PURPOSES 5 Sheets-Sheet 5 Filed Oct. 8, 1958 United States Patent O 3,120,765 MSH-SPEED ANGLE-HANDPEECES EUR DENTAL PURPSES Erich Hoffmeister and Kurt Rhm, Biberach (Riss), Germany, assignors to Alois Kaitenhach and Erich Hudrneister, the responsible partners of Kaitenbach il Voight, a kommanditgeseiischait, Biberach (Riss), Germany rues on. a, 195s, ser. No. 766,095 Ciaims priority, application Germany Get. 10, 1957 il@ Ciaiins. (Cl. 32--Z7) High-speed angle handpieces for dental purposes are already known wherein the tool rotates at speeds of 100,000 revolutions per minute and above.

In one kind of high-speed angle handpieces for dental purposes of this kind, the very high rpm. speeds for the tool are achieved by means of an impeller which is driven by compressed air and which is arranged either at the re-ar end of the instrument or in the angle handpiece head.

In high-speed angle handpieces having an impeller arranged in the head, and which can either be constructed as straight-shank or elbowedeshank handpieces, the supply and at least partly also the discharge of the compressed air used for driving the impeller, and also the supply of water to the front end of the angle handpiece head are effected from the rear end of the instrument, to which the supply hoses for the compressed air and the water are connected.

The high-speed angle handpieces of this kind are of one-piece construction over their entire length. Consequently, more particularly when lime-containing water is used, it is possible that in the course of time the water pipe which extends through the entire instrument and which in fact is of only very small diameter, will become blocked. In this case, it is very diiiicult to clean the relatively long and possibly also elbowed water pipe, since the pipe can only be cleaned by means of a long exible wire which has to be passed gradually through the pipe, removing the incrustation as it goes. In order to avoid this disadvantage, which markedly limits the usefulness of the instrument as far as the dentist is concerned, it is proposed according to the invention that the instrument be divided transversely of its length at some distance from the head, together with the pipes for the compressed air supply and discharge and the water pipe, and to arrange at the place of division a packing which when the two parts of the instrument are connected, expediently by screwing, seals the divided pipes relatively to the exterior at the joint.

Expediently, the pipes coming from the rear end of the instrument project some distance through the packing disc arranged at the front end of the rear part of the instrument, and are inserted with some clearance into the correspondingly widened pipes leading to the head of the instrument, in such a manner that the free ends of the pipes leading to the head of the instrument bear with a sealing action against the packing disc when the two parts of the instrument are joined together.

In the forward part of the instrument, the pipes are advantageously formed by machining from the substantially solid head casing which extends from the turbine housing.

The pipe for discharging the compressed air in the forward part of the instrument can also debouch at the packing disc and can be continued in the rear part of the instrument through a perforation in the packing disc and in the shank elbow piece, which serves as an abutment for the packing disc, so that the said pipe opens into the chamber within the handle tube. The discharge of compressed air from the handle tube at the ICC rear part of the instrument can be effected either through the rear end or through one or more holes arranged about the periphery of the rear end of the handle tube.

The division of the instrument transversely of its length according to the invention makes it readily possible to clean the water pipe if it happens to become soiled. Also, it is easy for the dentist himself to carry out any cleaning work which is necessary.

The invention considerably improves the usefulness of the instrument as far as the dentist is concerned.

A further object of the invention is to improve angle handpieces having an elbow piece in the shank thereof still further for the purpose of enabling the head to be set at any desired angle relatively to the shank elbow. The various angular adjustments for the head relatively to the shank elbow which have long been known in other dental instruments, are regarded by dentists as being extremely appropriate for carrying out various drilling and grinding operations.

ln order to solve the problem, according to the invention it is proposed to arrange the water supply pipes in the handle tube and in the head casing axially 0f the said parts and to make them open into an axial perfoi-ation in the packing arranged at the forward end of the shank elbow piece, whereas the air supply pipe in the head casing opens into an annular duct which is provided at the free end of the head casing or the forward end face of the packing and communicates through one or more perforations in the packing with the air supply pipe connected to these perforations. It is also proposed that the air return ducts in the head casing communicate in the same way through `a further annular chamber at the free end of the head casing or the forward end face of the packing and a plurality or perforations in the packing, with the interior of the handle tube.

Expediently, the air supply pipe in the handle tube and also the air discharge perforations in the shank elbow piece also open into annular ducts at the front end or" the shank elbow piece or the rear end face of the packing, which in their turn communicate through the perforations in the packing with the annular ducts at the other side of the packing. In this way, it is not necessary to iix the packing in a speciic position on the shank elbow piece. The packing can also rotate, rather, relatively to the shank elbow piece or relatively to the end of the head sleeve, Without thereby hindering in any way the free through passage of the supply air and discharge air.

It is particularly appropriate for the air supply pipes in the handle tube and in the head casing to surround concentrically the axially arranged water supply pipes, since in this way, whilst allowing adequate cross-sections, the minimum amount of space is required and the handle tube of the instrument need not be made unnecessarily thick.

For connecting the head casing to the shank elbow piece, it is expedient to secure a gripping ring rotatably, but axially non-displaceably, on the shank elbow piece, the free end of the head casing being adapted to be inserted lockably in the said ring, pressing the end face of the head casing tightly against the outer face of the packing.

The lockable connection can be effected by screwingin the head sleeve, but preferably by means of a bayonet joint.

High-speed angle handpieces having a shank elbow constructed according to the invention are illustrated by way of exampie in the drawings wherein:

FIG. 1 is a longitudinal sectional view of the novel high-speed angle handpiece with shank elbow piece,

FIG. 2 is a longitudinal sectional view taken on the line II--II of FIG. 5, and on a larger scale, of the forward part of the angle handpiece with the forward end of the rear part of the handpiece,

FIG. 3 is a longitudinal sectional View taken on the line Ill-III of FIG. 2 of the angle handpiece according to FG. 2,

FIG. 4 is a sectional View taken on the line IV-IV of FIG. 2, of the angle handpiece head,

FIG. 5 is a cross-sectional view taken on the line V-V of FEG. 2, showing the `sleeve connected to the angle handpicce head, with the ducts therein,

FIG. 6 is a longitudinal sectional View of the rear part of the instrument according to FIG. l, on a larger scale,

FIG. 7 is a longitudinal sectional view of another embodiment of the invention on a greatly enlarged scale of an angle handpiece head with the adjoining head sleeve and the elbow piece with the forward part of the handle tube, the head sleeve being shown separated from the elbow piece,

FIG. 8 is a sectional View taken on the line VIII- VIII through the angle handpiece head with the forward part of the head sleeve according to FIG. 7,

FIG. 9 is a cross-sectional view of the elbow piece taken on the line IX-IX of F IG. 7,

FIG. 10 is a view of the forward end face of the perforated packing arranged in the elbow piece,

FIG. 1l is a front View of the free end of the head sleeve,

FIG. 12 is a front view of the free end of the gripping ring.

The angle handpiece comprising an elbow piece in its shank according to FIGS. l to 6 consists of the forward part 1 of the instrument, which surrounds the actual angle handpiece head and the casing adjoining the head, the free end of the said sleeve extending approximately as far as the elbow piece 2, and of the rear instrument part 3 to whose rear end are connected the hoses (not shown) for the supply of compressed air and water.

The compressed air is admitted at the rear end of the instrument through the stub pipe 4 over whose free end the compressed air supply hose is fitted. The compressed air hose is clamped fast on the stub pipe l by means of the cap nut 5 which is screwed on the thickened inner end of the stub pipe 4. The thickened forward end of the stub pipe 4 comprises a relatively wide bore 6 which opens into the interior of the stub pipe 4, and a relatively narrow bore 7 into which the small pipe 3 is welded. The small pipe 8 is so bent that the free end is arranged axially in the stub pipe 4 and projects slifhtly out of the latter. Mounted on the end is a hose which is disposed inside the hose which supplies the compressed air. Water is admitted through the hose which is arranged in the interior of the compressed air supply hose and which is placed on the free end of the small pipe 8. The compressed air pipe 9 engages with a slight clearance in the bore 6 of the stub pipe 4, whereas the water pipe 10 engages with some clearance in the relatively small bore 7.

Arranged over the thickened forward end of the stub pipe 4 is a cup sleeve 11 whose bottom wall 12 comprises perforations through which the pipes 9 and 10 are guided. At its rear end the cup sleeve is provided with an outwardly projecting flange 13. Arranged between the bottom wall 12 of the cup sleeve 11 and the rear thickened end portion of the stub pipe 4 is a packing disc 14 which also comprises perforations through which the pipes 9 and 10 extend. When the cap nut 15 is tightened, screwing on to the rear end of the handle tube 16, the outwardly projecting iiange 17 of the stub pipe 4 is pressed against the tiange 13 of the cup sleeve 11 and this latter tiange is pressed against the rear end of the handle tube 16, with simultaneous compression of the packing disc 14 thus sealing the pipes 9 and 10 in the perforations 6 and 7.

A shank elbow piece 2 is welded into the forward end of the handle tube 15, which can also be further divided transversely of its length at 18 by a screwed connection. A packing disc 19 bears against the forward end face of the elbow piece 2. An internally grooved ring 21 is screwed on to an external screwthread 2t) of the elbow piece 2. A packing 19 engages in the inner groove of this ring, so that the said packing is secured in the axial direction against falling out. An internal collar 22 of a clamping nut 23 engages over the inner end face of the grooved ring 21, said nut 23 being provided internally at its free end with a screwthread 24. The ducts 9 and 19 for the supply of compressed air and water respectively are welded at their bent-over forward ends into corresponding perforations in the elbow piece 2 and engage through the packing disc 19, which is provided with corresponding perforations.

The forward instrument part l consists of the actual angle handpiece head 25 and the adjoining head casing 26 which is connected to the head 2S by welding. Welded into the casing 26 and forming a part thereof is an insert piece 27 which is provided with longitudinal bores 23 and 29 for the supply of compressed air and water respectively. The free ends of the pipes 9 and 1G engage into the rearward ends of the bores 28 and 29. The casing 26 adjoining the head 25 is provided at its rear thickened end with a screwthread 30. After the free ends of the tubes 9 and 1l) are inserted within bores 28 and 29 the rear of the forward instrument, part one is connected fast to the forward section of the rear instrument part 3 by turning the clamping nut 23, which screws on to the screwthread Si) of the sleeve 26. The clamping nut 23 is rotated until the end face 31 of the insert piece 27 bears with a sealingtight action against the packing disc 19. The forward ends of the pipes 9 and 1t) are thereby satisfactorily sealed.

The rear opening in the head can be closed by a closure cap 32. Arranged within the head 25 is the impeller housing which consists of the forward half 33 and the rearward half 34. Arranged within this transversely divided impeller housing is the impeller wheel 35 whose shaft is mounted in ball bearings 36, 37 whose outer races are held partly in the transversely divided impeller housing, partly in the forward head portion and partly in the closure cap 32. After the closure cap 32 is taken off, the entire impeller with the two bail bearings in the impeller housing can be removed rearwardly from the head.

The tool carried by the impeller 35 can be secured interchangeably within the hollow impeller shaft, with the interposition of a plastic bushing, or other known bur shaft carrying means.

As FIG. 3 shows, the compressed air is fed from the end of the bore 28 through a bore 3S which also extends through the impeller housing, and impinges substantially tangentially on the impeller wheel. The discharge of the compressed air which has been used for driving the impeller is effected partly through the rear ball bearing 37 through a plurality of holes 39 in the closure cap 32 towards the exterior, and partly outwardly through the forward ball bearing through three small holes 4t) which are each oliset by relatively to one another, in the front wall of the head as near as possible to the hollow impeller shaft. The greatest part of the compressed air, however, is discharged after flowing through the impeller, through the recess 41 in the impeller housing through the duct 42 (see FIGS. 3, 4, 5) in the insert piece 27, through a hole 43 in the packing disc 19 and a correspending hole 44 in the elbow piece 2 and into the interior of the handle tube 16, and is discharged towards the exterior through holes 45 in the rear end of the handle tube.

The water, which is conveyed through the pipe 10 and the bore 29 in the insert piece 27, is guided under slight pressure to the exterior from that end of the bore 29 adjoining the angle handpiece head by means of a hole 46 which is disposed obliquely to the impeller axis, the issuing jet of water being atomised through the three streams of compressed air issuing from the holes 40 to form a fine mist of water. This water mist serves to J reduce the frictional heat caused during drilling and grinding.

In the case of the angle handpiece with shank elbow and pneumatically driven impeller arranged in the handpiece head as illustrated in FIGS. 7 to l2, the construction of the actual head corresponds to the constructional form according to FIGS. l to 6. The actual handpiece head l with the air impeller 52 arranged within the head is followed by the head sleeve 53 which is provided with an insert piece 54.

Arranged axially of the insert piece and therefore of the entire head casing is a water supply pipe 55 from whose head-side end a thin pipe 56 is disposed obliquely to the axis of the head, so that the Water issuing from this pipe impinges on the tool (not shown). Situated in the rearward part of the insert piece 54 is a central bore 57 which widens at 58 towards the free end of the head sleeve. Inserted in a recess at the end of the insert piece 54 is a ring 53 which with the ring portion 6i) supports the central water supply pipe 55. This ring 59 is provided with peripherally distributed perforations 6l, which at the inner side open into the widened duct 62 surrounding the water supply pipe S5, and at the outer side open into the annular chamber 63.

Connected to the inner end of the duct 57 is the duct 64 which extends obliquely into the impeller housing. The air required for operating the impeller is supplied thereto through the annular chamber 63, the perforations 6l, the widened duct 62, the duct 57 and the duct 64.

The discharge air from the impeller is taken from the impeller housing through the recess 65 in the insert piece 54 into the annular duct 66 and thence through a plurality of bores 67 distributed about the periphery into the annular chamber 68 arranged concentrically to the annular chamber 63. The free end faces of the water supply pipe 55 and of the walls of the annular chambers 63 and 66 all lie in the same plane as one another.

rl`he head sleeve 53 carries studs 69 at two diametally oppositely situated points at some distance from the free end face of the head sleeve.

The shank elbow piece 71 is mounted on the forward end of the handle tube 7i). Elbow piece and handle tube are connected fast to one another, preferably by brazing. By means of a spring ring 72 the gripping ring 73 is connected rotatably but axially non-displaceably to the elbow piece, the wall of the said gripping ring comprising at the width of the studs 69 of the head sleeve 53, at diametrally opposite points, axially disposed ducts 74 which merge into oblique transverse ducts 75 in order to permit a bayonet joint connection to be elfected.

inserted in the forward end face of the elbow piece 7l is an elastic packing 76, and expediently the recess at the end face of the elbow piece 7l is somewhat undercut in order thus to provide a better anchorage for the correspondingly constructed periphery of the packing. As FIG. l0 shows, the packing 76 comprises a central perforation 77 to which is connected the central perforation 78 of the elbow piece. Connected to the rear end of the perforation 73 is the water supply pipe 79, which extends axially through the handle tube 70 as far as the coupling (not shown) at the rear end of the instrument.

Arranged concentrically to the perforation 77 in the packing are a plurality of perforations {it} whose front ends open into the annular chamber 63 and whose rear ends open into the annular duct 3l in the elbow piece '71. From the annular duct Si, a plurality of ports 82 also lead into the air supply pipe S3 which is arranged concentrically to the water supply pipe 79, the pipes 79 and S3 being centered relatively to one another by the ring S4. The pipe 83 is centered in a recess in the rear part of the elbow piece '71.

The packing 76 also comprises, distributed about its periphery, perforations 85 which are also concentric to the perforation 77 and are preferably constructed as slots and which open into an annular duct 86 in the elbow piece 7l. The annular duct 86 communicates through perforations S7 in the shank elbow piece with the interior of the handle sleeve 7i). Therefore the discharge air from the impeller passes through the perforations SS of the packing and through the annular duct 86 in the elbow piece and through the perforations 87 in the elbow iece into the interior of the handle tube, from the end of which it is finally discharged in a manner known per se into the open air.

Before the instrument is started up, the head with the adjoining head sleeve is inserted so that the studs 69 run into the longitudinal ducts 74 in the inner wall of the gripping ring 73, whereupon by rotating the gripping ring 73 the studs 69 enter the transverse ducts 75 and in this way the end face of the head sleeve 53 is pulled with a sealing-tight action against the forward end face of the packing 76.

We claim:

l. A dental handpiece comprising a handle having a housing on one end enclosing an air-driven turbine rotor having means to connect thereto a dental tool for rotation by said rotor, and conducting means operable to transmit pressurized air and water longitudinally along said handle from the outer end thereof to said housing, said handle and conducting means being separable intermediately of the ends thereof and nearer said housing than said other end of said handle, and means operable -detachably to connect the separable portions of said handle and conducting means in a manner to position the separable portions of said conducting means in operable communication with each other, said conducting means including a plurality of conduits having terminal portions positioned adjacent the location of said means operable detachably to connect the separable portions, said lastmentioned means includ-ing a generally disc-shaped elastic packing member provided with a plurality of openings engageably receiving the terminal portions of said conduits respectively, said last-mentioned means including elements positioned in axial alignment on opposite sides of said packing member and axially movable toward each other to deform said elastic packing member into sealing engagement with the terminal portions of the conduits, said last-mentioned means also including coupling means fixedly attaching said housing to said handle.

2. The invention as delined in claim l, wherein said handpiece includes first and second separable portions, said housing being secured to one end of one of the separable portions, said means to connect the separable portions being arranged to position said one portion angularly with respect to the other portion.

3. The invention as defined in claim 2, wherein said conducting means for each of the separable portions terminate at the location of said elastic packing member in transversely disposed abutting planes to permit limited relative rotation of one of the portions with respect to the other about the longitudinal axis, said packing member being transversely disposed between said abutting planes to cooperate with the opposed terminal portions of said conducting means.

4. The invention as defined in claim l, wherein said terminal portions of the conduits extend through the respective openings in the elastic packing member, said packing member being radially deformed for said sealing engagement.

5. The invention as defined in claim l, wherein said last-mentioned means includes a sleeve rotatably received on one of said separable portions, said sleeve being axially fixed with respect to one of said portions, the other of said portions being provided with means cooperable with said sleeve upon rotation thereof to move said separable portions axially with respect to each other.

6. The invention as defined in claim 5, wherein one of the separable portions is threaded for operable engagernent with threads provided on said rotatable sleeve.

7. The invention as defined in claim 5, wherein one of the separable portions is provided with a radially projecting element operatively received in an oblique transverse duct provided in the rotatable sleeve.

8. In a dental handpece comprising a rst section having a housing for an air-driven turbine xediy secured at one end thereof, a second section having one end removably secured to the other end of the iirst section, a plurality of conduits in said handpiece for supplying pressurized air and water to the housing and for exhausting air therefrom, coupling means at the other end of the second section connecting said conduits with a source of air and water under pressure, said conduits being divided transversely of their length near the connection between said first and second sections, tirst elastically deformable disc means sealing the conduits at their points of division, and second elastically deformable disc means, said coupling means compressing the second disc means to seal the connection with said conduits at said other end of the second section.

9. The handpiece as dened in claim 8, wherein said rst and second elastically deformable discs are provided with `apertures and said conduits include air and water pipes extending through said apertures, and said coupling means compresses said second disc means in a direction along the axis of said pipes to urge the Walls of said apertures radially into sealing engagement with said pipes.

10. in a dental handpiece comprising a first section having a housing for an air-driven turbine iixedly secured at one end thereof, a second section having one end removably secured to the other end of the first section, a plurality of conduits in said handpiece for supplying pressurized air and Water to the housing and for exhausting air therefrom, said conduits being divided transversely of their length near the connection between said first and second sections, and elastically deformable disc means sealing the conduits at their points of division, said conduits including air and water pipes in said second section and bores in said irst section, said pipes having ends extending beyond the point of connection and extending into said bores, said disc means having apertures receiving said ends.

References Cited in the tile of this patent UNITED STATES PATENTS 2,054,859 Kitching Sept. 22, 1936 2,650,112 Kinkead Aug. 25, 1953 2,701,147 Summerville Feb. 1, 1955 2,799,93 Kern July 23, 1957 2,994,129 Tanner et al. Aug. 1, 1961 FOREIGN PATENTS 512,874 Great Britain Sept. 27, 1939 163,217 Austria June 10, 1949 91,261 Norway Jan. 25, 1958 

1. A DENTAL HANDPIECE COMPRISING A HANDLE HAVING A HOUSING ON ONE END ENCLOSING AN AIR-DRIVEN TURBINE ROTOR HAVING MEANS TO CONNECT THERETO A DENTAL TOOL FOR ROTATION BY SAID ROTOR, AND CONDUCTING MEANS OPERABLE TO TRANSMIT PRESSURIZED AIR AND WATER LONGITUDINALLY ALONG SAID HANDLE FROM THE OUTER END THEREOF TO SAID HOUSING, SAID HANDLE AND CONDUCTING MEANS BEING SEPARABLE INTERMEDIATELY OF THE ENDS THEREOF AND NEARER SAID HOUSING THAN SAID OTHER END OF SAID HANDLE, AND MEANS OPERABLE DETACHABLY TO CONNECT THE SEPARABLE PORTIONS OF SAID HANDLE AND CONDUCTING MEANS IN A MANNER TO POSITION THE SEPARABLE PORTIONS OF SAID CONDUCTING MEANS IN OPERABLE COMMUNICATION WITH EACH OTHER, SAID CONDUCTING MEANS INCLUDING A PLURALITY OF CONDUITS HAVING TERMINAL PORTIONS POSITIONED ADJACENT THE LOCATION OF SAID MEANS OPERABLE DETACHABLY TO CONNECT THE SEPARABLE PORTIONS, SAID LASTMENTIONED MEANS INCLUDING A GENERALLY DISC-SHAPED ELASTIC PACKING MEMBER PROVIDED WITH A PLURALITY OF OPENINGS ENGAGEABLY RECEIVING THE TERMINAL PORTIONS OF SAID CONDUITS RESPECTIVELY, SAID LAST-MENTIONED MEANS INCLUDING ELEMENTS POSITIONED IN AXIAL ALIGNMENT ON OPPOSITE SIDES OF SAID PACKING MEMBER AND AXIALLY MOVABLE TOWARD EACH OTHER TO DEFORM SAID ELASTIC PACKING MEMBER INTO SEALING ENGAGEMENT WITH THE TERMINAL PORTIONS OF THE CONDUITS, SAID LAST-MENTIONED MEANS ALSO INCLUDING COUPLING MEANS FIXEDLY ATTACHING SAID HOUSING TO SAID HANDLE. 